<!doctype html> 
<html> 
<head> 
    <meta charset="utf-8"> 
    <title></title> 
</head>
<body>

<script type="text/javascript">
	
	var a = [1,2,3];
	var b = a;
	var c = [1,2,3];
	var d = new Array(1,2,3);
	alert(a == b);//false o true
	alert(a == c);//true  o false
	alert(a == d);//true  o false
</script>
</body>
</html>